Re: [Kimchi-devel] [PATCH] Abstract vm element updater for common usage

From: Royce Lv <lvroyce(a)linux.vnet.ibm.com&gt; Different kinds of vm elements will be added through different libvirt apis, this patch abstract a framework for this update. Wrap correspondent libvirt api in vm element class, and format their own libvirt call parameters in each class. Signed-off-by: Royce Lv <lvroyce(a)linux.vnet.ibm.com&gt; --- src/kimchi/model.py | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 63 insertions(+), 2 deletions(-) diff --git a/src/kimchi/model.py b/src/kimchi/model.py index 2c6d3a1..0f82b61 100644 --- a/src/kimchi/model.py +++ b/src/kimchi/model.py @@ -78,7 +78,6 @@ ISO_POOL_NAME = u'kimchi_isos' GUESTS_STATS_INTERVAL = 5 HOST_STATS_INTERVAL = 1 VM_STATIC_UPDATE_PARAMS = {'name': './name'} -VM_LIVE_UPDATE_PARAMS = {} STORAGE_SOURCES = {'netfs': {'addr': '/pool/source/host/@name', 'path': '/pool/source/dir/@path'}} @@ -490,7 +489,13 @@ class Model(object): return dom def _live_vm_update(self, dom, params): - pass + try: + for key, val in params.items(): + element = VMElementDef.create(key, val, dom) + element.add_to_vm() + except libvirt.libvirtError as e: + raise OperationFailed("Cannot apply change on vm: %s", + e.get_error_message()) def vm_update(self, name, params): dom = self._get_vm(name) @@ -1510,6 +1515,62 @@ class LibvirtVMScreenshot(VMScreenshot): os.close(fd) +class VMElementDef(object):

+ @classmethod + def create(cls, elem_type, elemArgs, dom): + for klass in cls.__subclasses__(): + if elem_type == klass.elemType: + return klass(elemArgs, dom) + raise OperationFailed('Unsupported vm element type: %s' % elemArgs['type']) + + def __init__(self, elemArgs, dom): + self.dom = dom + self.elemArgs = elemArgs + + def add_to_vm(self): + """Live update domain with correspondant libvirt API. + This should be paired with cancel() operation to cancel failed update.""" + pass + + def delete_from_vm(self): + """Revert operation of live update vm.""" + pass + + @property + def _update_param(self): + ''' Subclasses have to override this method to actually generate the + update param.''' + raise OperationFailed('Update param generater is not implemented: %s' % self) + + +class VMDiskDef(VMElementDef): + elemType = 'disk' + + def __init__(self, elemArgs, dom): + super(VMDiskDef, self).__init__(elemArgs, dom) +

+ def add_to_vm(self): + self.dom.attachDeviceFlags(xml=self._update_param['xml'], + flags=libvirt.VIR_DOMAIN_AFFECT_CURRENT|libvirt.VIR_DOMAIN_AFFECT_CONFIG) + + def delete_from_vm(self): + self.dom.detachDeviceFlags(xml=self._update_param['xml'], + flags=libvirt.VIR_DOMAIN_AFFECT_CURRENT|libvirt.VIR_DOMAIN_AFFECT_CONFIG) +

+ @property + def _update_param(self): + self.elemArgs['readonly'] = "<readonly/>" \ + if self.elemArgs['target']['type'] == 'cdrom' else None + xml = """ + <disk type='{source[type]}' device='{target[type]}'> + <source file='{source[path]}'/> + <target dev='{target[name]}' bus='{target[bus]}'/> + {readonly} + </disk> + """.format(**self.elemArgs) + return dict(xml=xml) + + class StoragePoolDef(object): @classmethod def create(cls, poolArgs):